Method of assembling a curved roll-rack

ABSTRACT

A frame construction for the curved roll-rack of a continuouscasting apparatus, and a method of assembling the rack. The frame is formed of lower, middle and upper sections assembled in aligned end-to-end relation. Each section is pivotally mounted at its exit end and supported on base members at its entry end. The side plates of the sections carry reference pins cooperable with specially designed gauges for accurately positioning roll clusters on the sections, the sections with respect to each other, the base members with respect to the sections, and a bending-roll unit at the entry end of the roll-rack.

United States Patent [191 Anderton et al.

[451 Dec 17, 1974' l l METHOD OF ASSEMBLING A CURVED ROLL-RACK [73] Assignee: United States Steel Corporation, Pittsburgh, Pa.

[22] Filed: Dec. 19, 1973 [21] Appl. No.: 426,292

Related U.S. Application Data [62] Division of Ser. No. 265,379, June 22, 1972,

[56] References Cited UNITED STATES PATENTS 3,492,7l5 Maton 29/407 3,495,65l 2/l970 Rokop eta]. l64/282 X 3,550,672 l2/l970 Fasten l64/273 R 3,596,706 8/1971 Knorr et al. 164/282 3,633,655 l/l972 Hofmann 164/282 Primary Examiner-C. W. Lanham Assistant ExaminerVictor A. DiPalma Attorney, Agent, or Firm-Walter P. Wood [5 7] ABSTRACT A frame construction for the curved roll-rack of a continuous-casting apparatus, and a method of assembling the rack. The frame is formed of lower, middle and upper sections assembled in aligned end-to-end relation. Each section is pivotally mounted at its exit end and supportedon base members at its entry end, The side plates of the sections carry reference pins cooperable with specially designed gauges for accurately positioning roll clusters on the sections, the sections with respect to each other, the base members with respect to the sections, and a bending-roll unit at the entry end of the roll-rack.

8 Claims, 10 Drawing Figures Pmmm wi 1 H914 3,854,188

sum 1 0F 5 PATENTEL 5 I 7 sneer 2 or 5 PATENTE SEE} H974 SHEET 30F 3 METHOD OF ASSEMBLING A CURVED ROLL-RACK This is a division of application Ser. No. 265,379, filed June 22, 1972 (now abandoned). The subject matter of application Ser. No. 265,379 is shown and claimed in a continuation thereof, Ser. No. 426,293, filed Dec. 19, 1973 (now US. Pat. No. 3,841,389).

This invention relates to an improved frame construction for use in the curved roll-rack of a continuous-casting apparatus and to an improved method of assembling a curved roll-rack.

In a conventional continuous-casting operation, a workpiece of indefinite length (i.e. a continuously formed casting) travels through a curved roll-rack, which guides the workpiece as its direction of travel changes from substantially vertical to horizontal. The workpiece enters the curved roll-rack from 'a bendingroll unit above, or directly from a mold if a curved mold is used, and goes into a straightener as it leaves. A curved roll-rack commonly includes a large number of clusters of top and bottom idler rolls which engage opposite faces of the workpiece at close intervals. These rolls define a path which has a radius of curvature usually of at least about feet. Consequently a curved roll-rack is a massive mechanism, and it must be constructed with a high degree of precision in order not to damage the workpiece, which still has a liquid core at this stage and hence is delicate. The usual practice is to construct the frame of the curved roll-rack in sections and to assemble these sections in aligned end-to-end relationon a supporting structure at the site of the apparatus. Heretofore assembling the frame sectionswith the necessary precision has been a difficult operation, particularly since proper allowance must be made for thermal expansion which occurs when the curved rollrack receives a hot workpiece.

An object ofour invention is to provide a curved rollrack frame construction which itself is more readily assembled on a supporting structure than frames used heretofore and which facilitates assembling the entire curved roll-rack.

A further object is to provide an improved frame section for use in a vcurved roll-rack, which section is readily assembled in accurate relation with other similar sections and with its supporting means.

A further object is to provide a curved roll-rack frame constructed of base members and preferably identical lower, middle and upper sections which are readily assembled in an accurate relation on a supporting structure by use of simple specially designed gauges.

A further object is to provide an improved method of assembling a curved roll-rack. and particularly its frame, on a supporting structure.

In the drawings:

FIG. I is a side elevational view ofa curved roll rack in which a frame is constructed in accordance with our invention;

FIG. 2 is a side elevational view on a larger scale of the inside face of one of the side plates embodied in the frame shown in FIG. 1;

FIG. 3 is a fragmentary top plan view on line Ill-III of FIG. 2;

FIG. 4 is a side elevational view of the gauge we use in positioning the idler roll clusters on the frame sections;

FIG. 5 is a side elevational view showing the gauge of FIG. 4 in place on a frame section;

FIG. 6 is a vertical sectional view of the rack partially assembled;

FIG. 7 is a side elevational view of a gauge we use in positioning the base members at one end of each of the lower and middle frame sections;

FIG. 8 is a side elevational view of a gauge we use in checking alignment of the middle and upper frame sections with the section next below;

FIG. 9 is a side elevational view of the gauge we use in positioning the bending-roll unit after the curved roll-rack frame is assembled; and

FIG. 10 is a side elevational view of the gauge we use in checking the relative positioning of the upper frame section and the rolls of the bending-roll unit.

FIG. 1 shows a curved roll-rack which includes a frame constructed of lower, middle and upper sections 10,12 and 13 assembled in aligned end-to-end relation, a first fabricated base member 14 located between the lower and middle sections 10 and 12, a second fabricated base member 15 located between the middle and upper sections 12 and 13, and a third fabricated base member 16 located at the top of the upper section 13; The curved roll-rack is supported on a rigid structure which includes in part vertical columns 17 and 18 and horizontal beams 19 and 20. The base members 14 and 15 are mounted on beams 19 and 20, respectively, and the base member 16 on column 17. The supporting structure also includes similar columns and 18a and beams 19a and 20a at the opposite side of the rollrack on which we mount fabricated base members 14a, 15a and 16a similar to 14, 15 and 16 but of opposite hand (FIG. 6). The frame sections and base members are positioned on the supporting structure by a procedure in accordance with our invention hereinafter described. A straightener 21 and a bending-roll unit 22 of any standard or desired construction are supported at the exit and entry ends, respectively, of the curved rollrack.

In accordance with our invention. the three frame sections 10, 12 and 13 are of similar construction and preferably all alike. Each section comprises an opposed pair of side plates 23 and 23a and a plurality of transverse members 24 bolted to the side plates to form a rigid structure. As best shown in FIGS. 2, 3 and 6, the inside faces of the side plates 23 and 230 have raised pads 25 where each transverse member 24 is joined. Each side plate has a concave edge along which we weld a series of machine pads 26. Each pad 26 has a respective near-radial hold 27. We attach roll supports 28 of inverted T-shape to pads 26 with bolts 29 which pass throughholes 27 and carry nuts 30. Each support 28 spans two pads 26. The supports 28 carry clusters of bottom and top idler rolls 31 and 32 best shown in FIG. 5. We insert shims 33 between the supports 28 and the pads 26 to adjust the position of the idler rolls, as hereinafter explained. FIG. 1 shows driven rolls 34 supported between each opposed pair of base members. but the present invention is not concerned with the arrangement ofdriven rolls, and no further description is deemed necessary.

On the radii of the concave edge of each side plate on which the axes of each pair of top and bottom idler rolls 31 and 32 are situated, we drill holes in pads 26 and insert transverse reference pins 35. Preferably these pins project inwardly of the side plates 23 and 23a, although they can project outwardly or in both directions. We drill holes 36 in each side plate 23 and 23a near one end where each section is to be pivoted to a support (i.e., the straightener or base members). We drill lower and upper holes 37 and 38 on radii near the center of the side plates. As hereinafter explained, the lower holes 37 in the side plates of the lower and middle frame sections and 12 and the upper holes 38 of the upper section 13 are located to coincide with predetermined working points when the sections are properly positioned. Our purpose in including both holes in the side plates of all three sections is to standardize the construction of the sections. We locate all the holes in the side plates 23 and 23a and pads 26 precisely, preferably using a numerical control horizontal boring mill or equivalent. We also machine the upper faces of pads 26 to locate each face a precise predetermined distance from the respective reference pin 35. In assembling the sections we may use holes 37 and 38 as references, but for greater precision we prefer to insert pins bearing crosshairs in the holes.

We may install the roll supports 28 and the clusters of idler rolls 31 and 32 on the frame sections 10, 12 and 13 either before we assemble the sections with one another or afterward, but we have found it easier to install the supports and rolls beforehand. In either instance we use a gauge 45, shown in detail in FIG. 4, for positioning the supports and rolls on the frame sections. Gauge 45 includes a C-shape body 46, an integral hub 47 on the lower end of the body, and a conventional dial'indicator 48 mounted at the end of the upper arm of the body. Before installing the roll supports and rolls, we determine the precise constant spacing required between each reference pin 35 and the diametrically opposite face of the corresponding bottom idler roll 31 to afford an accurate path for the workpiece. We set the dial indicator to read zero when the spacing is accurate.

We place hub 47 over the pin and contact the diametrically opposite face of the bottom idler roll with the plunger of the dial indicator 48, as shown in FIG. 5. We insert shims 33 as required to provide the correct spacing. All the clusters of bottom idler rolls are interchangeable with one another, and likewise all the clusters of top idler rolls. Once we have positioned the roll supports 28 accurately, we can remove or replace idler roll clusters without disturbing the setting of their supports 28. Some of the roll clusters must be absent to accommodate the gauges which we use in assembling the rack sections with one another, as hereinafter explained.

Horizontal and vertical tangent lines, along which the outside or convex face of the casting travels in straight lines after leaving the curved roll-rack and before entering it, are indicated at H and V respectively in FIG. 6. The vertical radius perpendicular to H is indicated at R. Before our invention comes into play, the col- L mits and beams ot'the supporting structure have been erected, the straightener 21 is in place thereon, and the lines H, V and R are determined. We next determine a series of working points which will bear a predetermined relation to specific points of the curved roll-rack when the frame sections and base members are properly positioned. The first working point WP, lies at the intersection of lines H and R. The second and third working points WP and WP;, lie on line H predetermined distances to the left of WP Line H and the three working pointsthereon are approximately even with the upper face of beam 19. The fourth working 7 point WP, lies a predetermined distance to the right of line V and a predetermined distance above line H. The fifth and sixth working points WP and WP,, lie on line V predetermined distances above line H.

In the ensuing description the term exit" and entry" refer to the travel of the workpiece through the curved roll-rack. Thus the exit end is toward the right as viewed in FIGS. 1 and 6. We start at the exit end in assembling the frame sections and base members. To simplify the description, we describe only the procedure we follow in assembling parts at the side of the roll-rack shown in FIG. 6. We of course follow a similar procedure in assembling the parts at the side shown in FIG. 1. To simplify FIG. 6, the roll supports 28 and roll clusters 31 and 32 have been omitted therefrom.

We install the base member 14a on beam 19a in a position which roughly corresponds with its final position. To do this, we place the transverse center line of the base member over WP Next we mount the exit end of the lower frame section 10 on the straightener 21 with a first pivot pin 39 which passes through hole 36 in the side plate 23a and a corresponding hole in the straightener frame. We pivotally adjust the lower section about pin 39 to place the lower hole 37 on the horizontal tangent line H, thereby accurately positioning this section. The point on the horizontal tangent on which hole 37 lies is WP We install a gauge 49, shown in detail in FIG. 7, on the lower section. (In FIG. 6 weshow gauge 49 installed on the middle section 12, but its use on the lower section 10 is identical.) Gauge 49 includes a sloping arm 50 and a horizontal arm 51. Arm 50 has at least two holes 52, but preferably three, spaced to' receive a corresponding number of the reference pins 35 at the entry end of the lower section. Arm 51 has a hole 53. We adjust the position of the base member 14a to align a hole therein with hole 53, and inserta second pivot pin 54 through the aligned holes. We place shims 55 under the base member to raise it to the proper height. The base member carries an adjustable wedge-shaped pad 56 on which the entry end of the side plate 23a rests. We place shims 57 under pad 56 to enable the pad to support the entry end of section 10 at the proper angle. We bolt the entry end of the side plate to the base member with bolts 58 which pass through enlarged openings in the side plate to permit the side plate to undergo thermal expansion and contraction.

We install the base member 15a on beam 20a in a position which roughly corresponds with its final position. To do this, we place a given transverse line on the base member over WP Next we mount the exit end of the middle frame section 12 on the base member 14, with its hole36 receiving the second pivot pin 54. Gauge 49 of course has been removed. We pivotally adjust the middlesection about pin 54 to align the lower hole 37 with WP. We know the location of WP only by calculation, but we can sight on the hole to place it at the location we have determined. This procedure should position the middle section 12 accurately with respect to the lower section 10, but we prefer to check the positioning with a stepped gauge 62 shown in detail in FIG. 8. Gauge 62 has a series of steps 63 along its lower edge to the right of its midpoint and another series 64 to the left. Steps 63 are spaced to fit over a corresponding number of thereference pins 35 on the lower frame section 10, while steps 64 are spaced to fit over a corresponding number of the reference pins 35 on the middle frame section 12. If the pins fit exactly in the steps, the middle section is positioned accurately. The roll supports 28 do not interfere with use of gauge 62, but the roll clusters 31 and 32 must be absent from the portions of the frame sections spanned by the gauge. We again employ gauge 49 in the same manner as before to position the base member a accurately, and insert a third pivot pin 65 through hole 53 and a corresponding hole in the base member. Shims 66, a pad 67, shims 68 and bolts 69 bear the same relation to the base member 15a as the corresponding parts associated with the base member 14a.

We install the base member16a at its proper elevation on column 17a, and we mount the exit end of the upper frame section 13 on the base member 150 with its hole 36 receiving the third pivot pin 65. We pivotally adjust the upper section about pin 65 to align its upper hole 38 with WP thereby accurately positioning this section. We may insert a pin in hole 38 to facilitate this adjustment. The entry end of the side plate 23a of the upper section bears directly against the base member 16a. We place shims 71 under the base member 160 to hold the upper section in its proper position. We use the stepped gauge 62 again to check the position of the upper section with respect to the middle section 12. The roll clusters may be returned to the rack, or installed if this was not done beforehand.

The foregoing steps complete the assembly of the curved roll-rack. Next we install the bending-roll unit 22 and its supporting structure, which includes fabricated bases 72 and 72a resting on the tops of columns 17 and 17a, respectively. The upper faces of bases 72 and 72a carry fixed pads 73. We use a gauge 74, shown in detail in FIG. 9, to position base 72a. Gauge 74 includes a depending arm 75 and a block 76. Arm 75 has two holes 77 spaced to receive the two upper reference pins 35 of the upper section 13. The block 76 has vertical and horizontal edges 78 and 79 formed accurately at right angles to each other. We install gauge 74 on the upper section and position base 720 so that its right face abuts the vertical edge 78 of-block 76, as shown in FIG. 6. We insert shims 80 between the base 72a and the column 17a to position the base at the proper height. Next we bolt the previously assembled bendingroll unit 22 in place on its support with the bottom of the unit at the same elevation as the horizontal edge 79 of block 76. Preferably, we check the alignment of the bending-roll unit and upper section 13 with a gauge 81 shown in detail in FIG. 10. Gauge 81 includes depend ing and upstanding arms 82 and 83. The depending arm has two holes 84 spaced to receive the two upper reference pins 35 of the upper section 13. If the parts are positioned accurately, the upstanding arm 83 abuts the inside face of the lowermost roll 85 of the bending-roll unit when the gauge is installed on the upper section.

We prefer that the reference pins 35 project inwardly of the side plates 23 and 23a in order that we may use them for positioning the idler roll clusters, as well as for positioning the frame sections, base members and bending-roll unit. After the curved roll-rack has been in use, it is desirable occasionally to recheck the position of the parts. If the pins 35 project outwardly or in both directions, the stepped gauge 62 can be installed without removing the idler roll clusters. Hence there is an advantage to using pins which project in both directions.

From the foregoing description it is seen that our invention affords a simple sectional frame construction for a curved roll-rack. The construction facilitates accurately positioning the various parts of the rack. The invention also affords a method of expeditiously and accurately assembling the rack to the necessary degree of precision. In an actual installation of a roll-rack of 30-foot radius, specifications called for an accuracy of +0.0l8 inch, 0.000 inch, in the radius. With our invention we achieved an accuracy of +0.004 inch in this radius.

We claim:

I l. A method of assembling a curved roll-rack in relation to surrounding structure comprising pivotally mounting a lower frame section at its exit end on a fixed body at the exit end of the rack, accurately positioning said lower frame section by aligning a predetermined accurately marked point thereon With'a predetermined working point on the surrounding structure, roughly positioning a base member at the entry end of said lower section, accurately positioning the base member with a gauge which engages reference pins on said lower section, and repeating the foregoing steps to position a middle section on said base member, another base member at the entry end of said middle section, and an upper section on said second-named base member.

2. A method as defined in claim 1 comprising a further step of checking the positioning of said sections with respect to one another with a gauge which engages reference pins on adjacent sections.

3. A method as defined in claim 1 comprising a further step of positioning roll clusters on said frame sections with a gauge which engages said reference pins.

4. A method as defined in claim 3 in which said roll clusters are installed accurately on said sections before the sections and base members are assembled on each other, and certain of said clusters are removed to enable gauges to be installed on said reference pins.

5. A method as defined in claim 1 in which the predetermined points on said sections lie on radii near the center of said sections, which sections are formed arcuately.

6. A method as defined in claim 1 in which said working points are located beforehand in relation to horizontal and vertical tangent lines along which a workpiece travels after leaving said rack and before entering.

7. A method as defined in claim 1 in which a bendingroll unit is installed at the entry end of the curved rollrack after the rack is assembled using gauges which engage reference pins on said upper section to position said unit.

8. A method as defined in claim 1 in which the same reference pins along the concave edge of said sections are used to position (a) roll clusters on said sections, (b) said sections with respect to each other, (c) said base members with respect to said sections, and (d) a bending roll unit with respect to the assembled rack. 

1. A method of assembling a curved roll-rack in relation to surrounding structure comprising pivotally mounting a lower frame section at its exit end on a fixed body at the exit end of the rack, accurately positioning said lower frame section by aligning a predetermined accurately marked poinT thereon with a predetermined working point on the surrounding structure, roughly positioning a base member at the entry end of said lower section, accurately positioning the base member with a gauge which engages reference pins on said lower section, and repeating the foregoing steps to position a middle section on said base member, another base member at the entry end of said middle section, and an upper section on said second-named base member.
 2. A method as defined in claim 1 comprising a further step of checking the positioning of said sections with respect to one another with a gauge which engages reference pins on adjacent sections.
 3. A method as defined in claim 1 comprising a further step of positioning roll clusters on said frame sections with a gauge which engages said reference pins.
 4. A method as defined in claim 3 in which said roll clusters are installed accurately on said sections before the sections and base members are assembled on each other, and certain of said clusters are removed to enable gauges to be installed on said reference pins.
 5. A method as defined in claim 1 in which the predetermined points on said sections lie on radii near the center of said sections, which sections are formed arcuately.
 6. A method as defined in claim 1 in which said working points are located beforehand in relation to horizontal and vertical tangent lines along which a workpiece travels after leaving said rack and before entering.
 7. A method as defined in claim 1 in which a bending-roll unit is installed at the entry end of the curved roll-rack after the rack is assembled using gauges which engage reference pins on said upper section to position said unit.
 8. A method as defined in claim 1 in which the same reference pins along the concave edge of said sections are used to position (a) roll clusters on said sections, (b) said sections with respect to each other, (c) said base members with respect to said sections, and (d) a bending roll unit with respect to the assembled rack. 